• Journal of the Korean earth science society
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• v.37 no.7
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• pp.420-433
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• 2016

The purpose of this study is to improve the calibration matrixes of 2-D and 3-D convective rainfall rates (CRR) using the brightness temperature of the infrared $10.8{\mu}m$ channel (IR), the difference of brightness temperatures between infrared $10.8{\mu}m$ and vapor $6.7{\mu}m$ channels (IR-WV), and the normalized reflectance of the visible channel (VIS) from the COMS satellite and rainfall rate from the weather radar for the period of 75 rainy days from April 22, 2011 to October 22, 2011 in Korea. Especially, the rainfall rate data of the weather radar are used to validate the new 2-D and 3-DCRR calibration matrixes suitable for the Korean peninsula for the period of 24 rainy days in 2011. The 2D and 3D calibration matrixes provide the basic and maximum CRR values ($mm\;h^{-1}$) by multiplying the rain probability matrix, which is calculated by using the number of rainy and no-rainy pixels with associated 2-D (IR, IR-WV) and 3-D (IR, IR-WV, VIS) matrixes, by the mean and maximum rainfall rate matrixes, respectively, which is calculated by dividing the accumulated rainfall rate by the number of rainy pixels and by the product of the maximum rain rate for the calibration period by the number of rain occurrences. Finally, new 2-D and 3-D CRR calibration matrixes are obtained experimentally from the regression analysis of both basic and maximum rainfall rate matrixes. As a result, an area of rainfall rate more than 10 mm/h is magnified in the new ones as well as CRR is shown in lower class ranges in matrixes between IR brightness temperature and IR-WV brightness temperature difference than the existing ones. Accuracy and categorical statistics are computed for the data of CRR events occurred during the given period. The mean error (ME), mean absolute error (MAE), and root mean squire error (RMSE) in new 2-D and 3-D CRR calibrations led to smaller than in the existing ones, where false alarm ratio had decreased, probability of detection had increased a bit, and critical success index scores had improved. To take into account the strong rainfall rate in the weather events such as thunderstorms and typhoon, a moisture correction factor is corrected. This factor is defined as the product of the total precipitable waterby the relative humidity (PW RH), a mean value between surface and 500 hPa level, obtained from a numerical model or the COMS retrieval data. In this study, when the IR cloud top brightness temperature is lower than 210 K and the relative humidity is greater than 40%, the moisture correction factor is empirically scaled from 1.0 to 2.0 basing on PW RH values. Consequently, in applying to this factor in new 2D and 2D CRR calibrations, the ME, MAE, and RMSE are smaller than the new ones.

• Management & Information Systems Review
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• v.29 no.4
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• pp.89-108
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• 2010

Social Network Service(SNS) indicates the service to promote mutual friendship built in online focused on social relation between people. While a demand and concern of the service gets higher now more than ever, there are a lack of the approach in aspect of both technology and service still. 'Facebook' is the most famous in the world and the biggest in user number among various social network service. We investigate the key factors of 'Facebook' based on the side of approach both technology and service. We observe the behavior of users who have rich experience on using the social network service to find it. The result of this study reveals that an asynchronous method related to the technology drive to improve a sociality in social media. Furthermore, we find that openness connected with the technology force to intent the closed attribute in service through user observation. It is the unique qualities social media holds. The successful social network service can be expected if social media are developed to concern these factors.

• KDI Journal of Economic Policy
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• v.18 no.1
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• pp.3-72
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• 1996

본고(本稿)는 앞으로 전개될 세계화시대에 대비한 거시경제(巨視經濟)의 운영(運營) 및 정책(政策)의 개화방향(改華方向)에 관하여 논의하였다. 우선 본고(本稿)는 세계화의 진전에 따라 시장원리(市場原理)에 의한 간접관리적(間接管理的)인 경제운영(經濟運營)이 불가피하며 이를 위해서는 민간부문(民間部門)이 주도하는 경쟁적(競爭的) 시장경제추서(市場經濟秋序)를 정착시켜야 한다는 점을 강조하였다. 나아가, 한국의 거시경제운영상(巨視經濟運營上)의 문제점(직접규제(直接規制))에 의한 거시경제운영, 정책시계(政策視界)의 단기성, 그리고 거시경제정책에 대한 정치적 왜곡(歪曲)가능성)을 개선하고 경제세계화(經濟世界化)와 자유화(自由化)의 진전, 자본자유화(資本自由化)의 급진전, 그리고 급속한 정치적 민주화(民主化)등의 새로운 여건변화에 효과적으로 대응하기 위해서는 거시경제정책을 간접규제방식에 의해 운용하고, 정책시계(政策視界)를 중 장기화해야 하며, 세계경제정책협조체제(世界經濟政策協調體制)에 대한 참여를 준비해야 한다고 지적하고 있다. 다음으로 개별(個別) 거시경제정책운용(巨視經濟政策運用)과 관련해서는, 간접적(間接的)인 거시경제 운영체계가 쉽게 도입되는 방향으로, 통화정책(通貨政策)은 직접규제적 통화관리에서 벗어나 통화간접관리방식으로 전환하여야 하며 이의 기초가 되는 공개시장조작기능(公開市場操作機能)이 제고되어야 하고, 재정정책(財政政策)은 거시경제안정의 효과적 수단으로서 보다 더 그 역할이 강화되어야 한다. 또한 외환시장(外換市場)의 자유화와 더불어 환율(換率)에 보다 큰 신축성이 부여되어야한다. 나아가, 본고(本稿)는 소위 소규모개방경제하(小規模開放經濟下)에서의 통화 재정정책의 유효성 문제와 대내외 균형의 동시달성을 위한 통화(通貨) 재정정책(財政政策)의 조합문제를 논의하였다. 경직적(硬直的) 환율제도하(換率制度下)에서는 통화정책은 유효성이 없지만 재정정책은 유효성을 가지는 반면, 변동환율하(變動換率下)에서는 역으로 통화정책은 강력한 효과를 미치지만 재정정책의 유효성은 사라진다. 그리고 정책조합(政策組合)과 관련해서는, 대내균형을 위해서는 통화정책(通貨政策)을, 대외균형을 위해서는 재정정책(財政政策)을 할당하는 것이 합리적이라는 결론에 이르게 된다. 다음으로 자본자유화(資本自由化)과정에서의 거시정책조합과 관련해서는 기존의 연구와 선진국들의 경험에 비추어 볼 때, 현재와 같은 성격의 자본유입압력(資本流入壓力)에 대해서는 신축적(伸縮的)으로 환율변동(換率變動)을 허용하면서 통화량(通貨量) 목표를 유지하는 정책이 바람직한 정책조합(政策組合)이라는 결론에 이르게 되었다.

• KIISE Transactions on Computing Practices
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• v.22 no.7
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• pp.338-343
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• 2016

Today, opinion reviews on the Web are often used as a means of information exchange. As the importance of opinion reviews continues to grow, the number of issues for opinion spam also increases. Even though many research studies on detecting spam reviews have been conducted, some limitations of gold-standard datasets hinder research. Therefore, we introduce a new dataset called "Paraphrased Opinion Spam (POS)" that contains a new type of review spam that imitates truthful reviews. We have noticed that spammers refer to existing truthful reviews to fabricate spam reviews. To create such a seemingly truthful review spam dataset, we asked task participants to paraphrase truthful reviews to create a new deceptive review. The experiment results show that classifying our POS dataset is more difficult than classifying the existing spam datasets since the reviews in our dataset more linguistically look like truthful reviews. Also, training volume has been found to be an important factor for classification model performance.

• The KIPS Transactions:PartD
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• v.8D no.2
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• pp.175-180
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• 2001

This paper presents the optimal fraction of validation set to obtain a prediction accuracy of software failure count or failure time in the future by a neuro-fuzzy system. Given a fixed amount of training data, the most popular effective approach to avoiding underfitting and overfitting is early stopping, and hence getting optimal generalization. But there is unresolved practical issues : How many data do you assign to the training and validation set\ulcorner Rules of thumb abound, the solution is acquired by trial-and-error and we spend long time in this method. For the sake of optimal fraction of validation set, the variant specific fraction for the validation set be provided. It shows that minimal fraction of the validation data set is sufficient to achieve good next-step prediction. This result can be considered as a practical guideline in a prediction of software reliability by neuro-fuzzy system.

• The Journal of the Korea Contents Association
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• v.8 no.6
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• pp.167-174
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• 2008

The application of tape is being widely used for treatment of the musculoskeletal disorders and injury prevention. The techniques of the tape application has been relied on empirical evidence in preference to the neurophysiological evidence. Thus, the mechanism of taping has to be elucidated further. In this study, we assessed the effect of the elastic and non-elastic tape upon the gastrocnemius ${\alpha}$-motor neuron excitability using the gastrocnemius H-reflex. The amplitude of the M-wave and H-reflex were measured across three conditions: before tape application, with tape and with the tape removed. No significant changes of the excitability of the ${\alpha}$-motor neuron were obtained across three condition, either in the elastic and non-elastic tape. This results were quite different with other recent studies, which needs to be explored further.

• Journal of the Korea Society of Computer and Information
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• v.15 no.10
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• pp.183-190
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• 2010

The present study attempted to identify the metacognitive strategies used by L2 writers at the university level as well as their particular aspects which might influence the use of these strategies. Twenty-seven participants, all of whom were enrolled in an English course, were asked to write an expository essay and then complete a questionnaire which includes their beliefs and attitudes toward L2 writing experience and the metacognitive strategies during the writing process. It was found that even though inexpert writers knew and employed as many strategies as the expert counterparts did, they were unsuccessful in the quality of their texts. Simply possessing a repertoire of metacognitive strategies was not enough for successful L2 writing. The failure of the inexpert writers to apply these metacognitive strategies in an effective manner was influenced by affective factors such as anxiety, self-confidence, self-concept, etc. As a result of this study, a pedagogical implication is suggested.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.1
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• pp.87-91
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• 2005

The cascade-correlation (CC) learning algorithm of Fahlman and Lebiere is one of the most influential constructive algorithm in a neural network. Cascading the hidden neurons results in a network that can represent very strong nonlinearities. Although this power is in principle useful, it can be a disadvantage if such strong nonlinearity is not required to solve the problem. 3 models are presented and compared empirically. All of them are based on valiants of the cascade architecture and output neurons weights training of the CC algorithm. Empirical results indicate the followings： (1) In the pattern classification, the model that train only new hidden neuron to output layer connection weights shows the best predictive ability; (2) In the function approximation, the model that removed input-output connection and used sigmoid-linear activation function is better predictability than CasCor algorithm.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.20 no.2
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• pp.209-214
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• 2020

The equitable partitioning problem(EPP) is classified as [0/1] binary skill existence or nonexistence and integer skill levels such as [1,2,3,4,5]. There is well-known a polynomial-time optimal solution finding algorithm for binary skill EPP. On the other hand, tabu search a kind of metaheuristic has apply to integer skill level EPP is due to unknown polynomial-time algorithm for it and this problem is NP-hard. This paper suggests heuristic greedy algorithm with polynomial-time to find the optimal solution for integer skill level EPP. This algorithm descending sorts of skill level frequency for each field and decides the lower bound(LB) that more than the number of group, packing for each group bins first, than the students with less than LB allocates to each bin additionally. As a result of experimental data, this algorithm shows performance improvement than the result of tabu search.

• Clinical and Experimental Pediatrics
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• v.46 no.10
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• pp.1024-1028
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• 2003

Influenza-associated encephalopathy is regarded as one of the major neurologic disease entities along with those of Reye syndrome, acute necrotizing encephalopathy, and myelitis which are known to be related to influenza virus, mostly type A. And it is being actively researched in Japan as it has caused a tremendous increase in the number of deaths from 1997 to 2002, but it has not been yet reported in the Korean pediatric medical community. It attacks those previously healthy children, who have not been vaccinated. Patients start with such symptoms as fever and common respiratory problems, but within 24 to 48 hours they suffer from seizures with acute mental deterioration, become worse, and suffer multiple organ failures including marked elevated transaminase levels as well as coagulopathy. It induces deaths in a couple of days after the symptoms appear or remains a serious neurologic sequelae. Confirmative diagnosis is used to demonstrate influenza viral infection. We report here a 37 month aged boy who was admitted to our hospital during the last influenza season under the diagnosis of influenza associated encephalopathy on the basis of serologic testing by hemagglutinin inhibition(HI). This is the first report confirmed by increased antibody titer of the influenza A virus in Korea.